python - Why aren't my @property decorators working? -

i'm working on little class, playing @property decorators. reason it's not working right.

class card:     def __init__(self, rank, suit):         self.rank = rank         self.suit = suit      @property      def rank(self):         return self._rank      @rank.setter     def rank(self, value):         valid_ranks = ["2", "3", "4", "5", "6", "7", "8", "9", "j", "q", "k", "a"]         if valid_ranks.index(value):             self._rank = value      @property     def suit(self):         return self._suit      @suit.setter     def suit(self,value):         self._suit = value      def show(self):         print "{}{}".format(self.rank, self.suit) 

i initialize object so: card("cheese", "ball"), , presumably should throw error. python happily rolls though , assigns "cheese" rank. what's going on here? other calls rank setter through assignment syntax seem happily ignore setter i've put in place. i'm running python 2.7.5.

you're using old-style classes. noted in the documentation, properties don't work old-style classes. derive classes object. e.g.:

class card(object):     ... 

in python 3 don't need this, because python 3 has new-style classes.